百分數應用
回答 (3)
2006-10-28 8:22 am
設大圓的面積為x
小圓的面積為y
x X 25% = y X 40%
x X 25% ÷ 40% = y
y = x X 62.5%
∴小圓面積是大圓面積的百分之62.5
小圓的面積為y
x X 25% = y X 40%
x X 25% ÷ 40% = y
y = x X 62.5%
∴小圓面積是大圓面積的百分之62.5
參考: 自己
2006-10-28 7:35 am
62.5%
2006-10-28 7:34 am
設大、小兩圓的半徑是 x , y ( x > y )
x^2 (pi) - y^2 (pi) = 25% x = 40% y
25% x = 40% y
0.25x = 0.4y
25x = 40y
40y = 25x
y = 5 / 8 x
y = 62.5%x
Therefore
小圓面積是大圓面積的 62.5%
x^2 (pi) - y^2 (pi) = 25% x = 40% y
25% x = 40% y
0.25x = 0.4y
25x = 40y
40y = 25x
y = 5 / 8 x
y = 62.5%x
Therefore
小圓面積是大圓面積的 62.5%
收錄日期: 2021-04-21 12:15:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061027000051KK04946